Pentagon lawyers have determined that Saddam Hussein has been a prisoner of war since American forces captured him on December 13, a US Defence Department spokesman said in Washington.

Despite that determination, US Secretary of State Colin Powell told CBS Television: "I don't know that he has been formally declared a prisoner of war."

That decision was up to the Pentagon, Powell said.

Whether or not Saddam is a prisoner of war could be key to how he is treated in captivity and eventually put on trial. The Geneva Conventions on treatment of prisoners of war forbid any kind of coercion in interrogations, for example.

A senior British official said Saddam had not yet given useful information. The official said US authorities were taking their time questioning Saddam in the hope that he might eventually open up.

Saddam is being held and interrogated by the CIA. Iraqi officials say he is being held in the Baghdad area.